1. Field of the Invention
The present invention relates to an extraction method for extracting a sample, such as blood, urine, sputum, saliva, nasal discharge, tear fluid, or feces collected by a sampling rod, from a collection section of the sampling rod, an extraction vessel used in the method, an extraction kit, and a valve expansion member.
2. Description of the Related Art
A method of testing a substance in a sample using an antigen-antibody reaction (immune reaction) or the like is widely applied to clinical examinations. For example, in a general test method using an antigen-antibody reaction, a test is performed in the following manner. That is, a sample, such as blood, urine, sputum, saliva, nasal discharge, tear fluid, feces, or the like, is collected using a sampling rod, such as a cotton swab, then the collected sample is extracted into a sample extraction solution in an extraction vessel, a sample solution in which the sample is extracted is brought into contact with a labeled antibody solution containing a labeled antibody labeled with a color identification substance, such as enzyme, noble metal colloid, colored latex, pigment, or the like to cause a specific reaction between the antigen in the sample and the labeled antibody for forming an antigen-antibody immune complex, and the amount of the immune complex is measured visually or as an optical change to perform a qualitative or quantitative measurement.
In the test method described above, an extraction vessel for extracting a sample from a collection section of the sampling rod is used in order to obtain a sample solution. For example, Japanese Unexamined Patent Publication No. 2009-036732 teaches a method for improving sample extraction efficiency by rubbing the swab of a cotton swab to which a sample is attached against a protrusion provided on an inner side wall of an extraction vessel.
In the method described in Japanese Unexamined Patent Publication No. 2009-036732, however, no matter how hardly the swab is rubbed against the protrusion, the extraction solution around the swab is absorbed again by the cotton swab when it is released from the compression. Thus, it causes a problem that a precious sample is wasted. The situation in which a sample reattached to a collection section of a sampling rod is discarded with the sampling rod is not limited to the case in which a test is performed using a cotton swab.
The amount of sample that can be obtained from a subject is limited and, therefore, it is desirable to use the collected sample efficiently without wasting as much as possible.
The present invention has been developed in view of the circumstances described above, and it is an object of the present invention to provide an extraction method, when extracting a sample collected by a sampling rod, such as a cotton swab or the like, from a collection section of the sampling rod, capable of taking most of the precious sample into an extraction vessel efficiently without wasting, an extraction vessel used in the method, and an extraction kit.
It is a further object of the present invention to provide a valve expansion member that allows, when a test is performed using an extraction vessel having a valve body with a valve opening having a diameter smaller than that of a collection section of a sampling rod and is capable of receiving a rod body of the sampling rod, easy insertion/extraction of the rod body of the sampling rod without attaching the sample to the valve body.